1. Field of the Invention
This invention relates to a wrapping and packaging device for use in covering substantially rectangular-shaped contents, which can be compressed in a vertical direction, such as piled-up items, with a packaging sheet such as craft paper. For example, the contents may be many piled-up papers, books, belt-like clothes, fabrics folded in a longitudinal direction or a zig-zag form, and many accumulated boxes. More particularly, this invention relates to a system in which substantially rectangular-shaped contents are placed above a packaging sheet supplied onto an elevator. The packaging sheet is folded in a substantial U-shape along the bottom surface and both opposing side surfaces of the contents at the packaging start position during descent of the elevator. Both ends of the packaging sheet are folded along the upper surface of the contents and wound on the surface.
2. Background and Material Information
As disclosed in Japanese Utility Model Publication No. 3-11125, there is provided a system in which a packaging sheet is supplied onto the elevator during its ascending operation. The contents are manually placed, at a predetermined position, on the packaging sheet after the elevator is stopped at its upper limit position. A switch is manually operated to cause the elevator to be lowered. Both ends of the packaging sheet are folded into a substantial U-shape, and overlapped along the upper surface of the contents. Thereafter, the contents are transported horizontally and a frictional rotating member abuts against one end of the folded packaging sheet, on the upper surface of the downstream end in the transporting direction, and the frictional rotation member is rotated. Thereby, one end of the packaging sheet is pushed back, under frictional resistance, in an direction opposite to the transporting direction, to fasten the sheet. At the same time, when the other end of the packaging sheet, folded on the upper surface, at the upstream side in the transporting direction, passes below the frictional rotating member, the lower end of the frictional rotating member, rotated by a motor, abuts against the other end of the packaging sheet. Thereby, the other end of the packaging sheet is forcibly pushed, under the frictional resistance of these two members, in the transporting direction and the packaging sheet is fastened. Thereafter, an adhering tape adheres to both ends of the packaging sheet to make a finished package without any looseness.
In addition, as disclosed in Japanese Patent Publication No. 3-14685, there is provided a device in which a packaging sheet is supplied onto the elevator during its ascent. After the elevator stops at its upper limit, the contents are manually placed at a predetermined position on a packaging sheet. A switch is manually operated, whereby the elevator is lowered to cause both ends of the packaging sheet to fold up into a substantial U-shape. The packaging sheet ends are overlapped along the upper surface of the contents, and its winding is completed. Subsequently, the wound contents are horizontally transported, from the elevator, to a discharging table by a transporting means. Both side flaps, at each of the feeding-out ends of the packaging sheet, are folded inwardly along the opened side surfaces of the contents. Thereafter, the upper flap of each of the extending ends is folded down along both side surfaces of the contents. Concurrently, the adhering tape, fed-out by a tape feeding-out mechanism, adheres to both overlapped side ends of the packaging sheet by an adhering mechanism, and is sealed. Then, the lower flap is folded along the outer side of the folded upper flap, and, the extreme ends of the outermost, overlapped lower flap are folded along the upper surface of the contents under an inward projection of a guide. The adhering tape, fed out by a tape feeding-out mechanism, adheres to the extreme end of the lower flap and the upper surface of the contents, by an adhering mechanism, and is sealed.
However, the prior art packaging devices described above, have some problems in that they do not function to compress the contents in a vertical direction, even if the packaging sheet can be tightened against the contents, because one end of the packaging sheet is moved, and fastened after winding of the packaging sheet around the contents. The packaging sheet may not be tightly wound, under a low fastening force, due to the fastening of the packaging sheet under a frictional resistance. The frictional resistance is generated by abutment between the lower end of the frictional rotating member and the packaging sheet. A low frictional resistance is caused by a narrow abutting area with the packaging sheet. In particular, when the contents are piled-up material, and can be compressed in a vertical direction, some clearances are produced between the contents and the packaging sheet because the packaged contents are compressed. This results in broken contents, and produces wrinkles in the packaging sheet.
In addition, the entire device is large due to the fact that the packaging start position and the packaging completing position are spaced apart in both vertical and horizontal directions. Furthermore, when the contents are mounted at the packaging start position by the manual operation of one worker, and the lowering of the packaged contents from the packaging completing position, are alternatively carried out, the amount of work is high and the processing may not be easily carried out. In view of the aforesaid circumstances, it is a first object of the present invention to tightly wind the contents of vertically compressed contents. A second object of the present invention is to provide the packaging start position and the packaging completing position as near as possible without delaying the packaging speed.